The soot pile extended all the way down the individual runners. Luckily, it had only left a small amount of oil residue on the cylinder head’s intake ports, as that generally requires removing the cylinder head to properly clean.
|A screwdriver, wire brush, and other tools knocked this filth loose. This is before using any solvents or delving into the runners themselves. Makes you want to take a shower just looking at it, doesn’t it?|
|These pipes are clean!|
Cleaning the intake manifold was done while we anxiously awaited our new clutch. In this project’s introduction, we hinted at a Dual Mass Flywheel (DMF) issue with our car. It was more than an issue, it was a disaster. Low engine speeds (which just about describes the entire rev range on this car) resulted in shaking throughout the car that could knock every filling out of a British smile. It felt as if someone had welded a 10lb weight to one side of the crank pulley. As it turns out, that’s about what had happened, except on the flywheel side of the engine. The DMF on these cars, much like the DMFs on every car, features a ring gear side, and a friction surface side. On some cars, there are what looks like dog engagement teeth supported by springs that allow some torsional variation, but there is no way the two masses would go out of alignment with each other because they’re rigidly connected in the middle. Not so for VW. The TDI DMF appears to be held together with some sort of high tech rubber, and that’s about it. While it seems to quell engine vibrations well enough when new, if they begin to fail, the two halves can migrate from each other. In our case, that migration resulted in the friction surface mass being HALF AN INCH off center. 15+lbs. 0.5″ off center. This is the kind of imbalance that would put the towel on one side of the washing machine imbalance to shame.
|Our failed DMF. Look carefully at how much of the ring gear you can see behind the friction surface. Note that the bottom left side appears much larger than the top right? Fail.|